Apparatus for chain manufacture



March 17, 1931. R, W, DULL 1,796,594

' APPARATUS FOR CHAIN MNUFACTURE Filed March l0' 1925 4 Sheets--Sheeil l fifi/67722;

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March 17, 1931. R W, DULL 1,796,594

APPARATUS FOR CHAIN MANUFACTURE Filed March 1o,4 1925 4 sheets-sheet 5 N5 mx B March 17, 1931. R, w BULL 1,796,594

- APPARATUS FR CHAIN MANUFACTURE Filed March l0, 1925 MLK Patented Mar. 17, 1931 UNIT-so STAT-'Es PATENT ori-rcs RAYMOND W. DULIa F CHICAGO, ILLINOIS, ASSIGNOR TO LINK-BILT COMPANY, OF

` 'i CHICAGO, ILLINOIS, AV CORPORATION OFILLINOIS APPARATUS` FOB CHAIN MANUFACTUBE alipucaapn ma laren 1o, i925. lseran 115414,4141

My invention relates to an 'apparatus for making chain from a strip of sheet metal stock, and particularly to a machine lfor the continuous making and automatic assembling 5 of the links into a chain= The general object of my ,invention is to produce chain ofthe type described which hook. and pintle tongues are stamped rom'the center of the link blank .and the hook and pintle end bars are bentto produce a chain, each link of which consists of fiat side bars, a relativelycylindrical hook at the end, and aypintle at theyother shaped for rotation within the hook of the link next adjacent. One object is to rovide a mechanism for producing `chain of t etype described, vvith maximum cheapness and simplicity. Another object is to provide a mechanism which shall stampthe hook and pintle `tongues from the center of the blank and curl them and the end bars into finished hooks and pintles with a minimum strain upon the metal of the blank, anda minimum weakening and distortion of the fibers ofthe metal. Another object isto provide a mechanism forproducing chain of thevtype described in which, by

scoring and by indenting each blank the tend-l ency of the end bars to tear out shall be reduced to a minimum. 'Another object is to provide a mechanism for producing chain of the described type in which the length of the blank as it passes through the device shall vary as little as possible during, and be reduced as little as possible, by the successive dieimpacts.' i

Other objects will appear from time to time in the courseof the specication and claims.

I illustrate my invention more or less Vdiagrammatically in the accompanying` drawings, wherein Y Figure 1 is a plan view terialoperated upon; p

A Figure 2 isa section along theline '2f-2 of Fi ure 1; y .Figure 3 is a bottom view of the strip; i Figure 4 isa skeleton side elevation of the punch and die;

Figure 5 is a' longitudinalisection of the punch and die; n Y

Figure 6 is a section on the line 6-6` of 50 Figure 4;

of the strip of madie block is from right to left, as shown in Figures 4 and 5. This ribbon or strip C of stock may be initially straightened and fed by any means not' herein shown, being guided into the machine, for exam le, by the rollers C1 channeled as 'at C, and s idably and rotatably mounted on the vertical ins C:i posi tioned at either side ofthe die bibcks.

Any suitable means may be used for feed ing .the stock into and for drawing the' completed'chain away from the space between die and punch by a step by step movement, the

stock being advanced one step between each i forming Vaction of the punch, and being moved forward at each step a distance e nivn alent to the length ofthe blank or space rom which the individual links are formed.

`E is an suitable punch element and El is a relative y resistant base or backing adapted to receive the individual punch elements which Will later be described in detail.

The progressive affect of the cooperation of the punch and die elements is shoivnin Figures 1, 2 and 3, and for the sake ofclarity the imlpressions on the blanks made by the indivi ual elements Will be shown in small letters corresponding to the capitals which indicate the punch or die elements making them.

i At the first ste the unch Gr shearing against the edge (E2 of tiiedie member G1 shears the end ofthe future hook tongue from the opposed edge or end of the future pintle tongue. The pintle ton ue remains lat 1n the plane of the stocli:v but t e outer len h of the ook tongue is forced downvvar l therefrom, and is sheared from the side ars for approximately two-thirds of its future bottom of the lank.

When the punch is withdrawn and the stock has moved forward another step the tongue g is positioned over the upwardly humped die member H. Asthe punch members H1 and H2 thrust the blank down the tongue g is 'bent upwardly from the blank and the pintle tongue h is severed from the side bars and bent upwardly about the creasing bead H3 on the punch element H. At the same time the longltudinal scoring knives H* score the topI of the blank and the opposed knives H5 score the bottom of the blank to outline the separation between the unsevered ortion of the hook tongue g and the side ars.

At the next step, the punch thrusts the blank downwardly against the die member J and its inclinedforward surface J1 completes the separation of the hook tongue, thrusting it still farther upwardly from the blank. Meanwhile the punch member- J 1 with its creasing bead Ja thrusts the pintle tongue against the forming surface J 4 of the die element J and bends it into substantial perpendicularity to the stock. v

At the next step the hook tongue and the hook end of the link are not further modified but the punch member K operating against the die member K1 at the same time rolls the pintle tongue into final position and crmps or bends the pintle cross bar downwardly from the plane of the stock. The pintle tongue and end bar are confined between and formed by the substantially arcuate forming v surface K2 on the punch K the downwardly inclined surface Ks on the die member K1 and the face Kls of the severing knife K".

yAt the next step the blank is positioned upon the die member L and the hook end bar is bent or crimped against the die surface L1 by the opposed arcuate` face Lz on the punch member K. Meanwhile the knife K* severs the blank from the stock, preferably without any preliminary transverse scoring between links, and the rearward surface Ke of the knife member serve asa stop to limit the downward movement of the hook cross bar during its formation. The severed link is held firmly in position upon the die member lL for example by the spring pads Ll5 which enga e the side bars, and which are downwar ly thrust for example by the spring L. Preferably a pair of such pads are used, or a upon or are pad or gripping. member which engages and operates against both side bars.

The pintle end bar, which at the precedln ste was completely formed, is not operate onv y the unch or die, but it is surrounded by the hook ton ue which is rolled about it by the punch member M with its arcuate formin surface M1. The die member M2 is provi ed with a more or less flattened or slightly arcuate upper surface Ma u on which the pintle bar rests. The incline forward. die surface M of the member M2 limits the downward or rearward movement of the hook end bar during the rolling of the hook and its rearward surface M limits the movement of the end of the hook as it is formed, thus controlling the diameter of the cylinder thus produced.

At the next step the severed and partly formed link` its pintle now surrounded by the hook of the preceding link is drawn forward with the chain, its side bars rest upon the downwardly and rearwardly inclined die member O, being held firmly in position thereon, for example by the spring pads vO1, compressed by the springs O. Its hook is then rolled about the pintle of the succeeding'link, as above described.

I n the formation of the chain, I employ op osed inwardly slotted edge gripping yo es P depending from the punch bloc and positioned at any suitable point along the strip. Since the side bars of the blank are not in any way crimped or deformed or severed until the pintle bar is operated on at the moment of severance of the preceding blank from the stock, it may be positioned at any point alongA the stock. I illustrate it herein, however, as positioned adjacent the second forming step. They are inwardly slotted as at P1, and provided with any suitable adjusting elements, for example the adjusting screws P2. The yokes are suspended ositioned at the lower ends of the plungers 3, herein shown as cylindrical, with cut away portions P4. They are spring pressed by the spiral springs P, the ledges Pe limiting their downward movement in engagement with the stops P7. It will be understood that the die block is cut away as at P1o to receive the yokes and thus to permit vthe stock to lie upon the die elements and to receive the impact of the punch elements, without heilig disengaged from the yokes.

I provide any suitable-supporting member R along which the finished chain may be lee' lll

drawn. I do not herein illustrate any spethe stock and the punch or die at the time of suoli forward movement, I provide means for lifting the entire strip of stock from the die and for suspending it between die and punch intermediate the forming impacts, and for giving it its forward movement when so suspended and out of contact with either punch or die.

In the form herein shown, I move the stri upwardly after each impact to a position su ficiently high above the die to enable the hook g, when downwardly turned, to clear the die member G1 as the stock 'is forwardly moved. At the same time, the stri is positioned at such a distance below tl e punch as to permit the hook tongue g to clear all the punch elements even when it is bent to its osition of maximum height above the stoc The yokes P, which en age the edges `of the stock with their slots 1 serve to lift the stock, and to hold it suspended while the stock is bein forwardly fed. The adjustment screws permit of minor variations in width of stock used, and enable the yokes to be adjusted with whatever accuracy is necessary.

The strip of stock C is fed into the space between the punch and dies, for exam le through the rollers C1 which are provi ed with a circumferential channel or groove of V-shaped cross section. The stock cannot be caught or jammed in the rollers, since the rollers rotate in response to forward movement of the stock. and thus prevent any tendency of the stock to clam between the rollers, the bottoms of the s ots or channels of the rollers being preferably positioned sufficiently far apart to permit a slight clearance. The rollers are vertically movable along the ins C and permit such upward and downwar movement of the stock as normally takes place.

In the form of punch and die herein shown, the portions of the lilik which are forced out of the normal plane of the strip are all bent upwardly toward the punch, save for the initial downward movement of the tongue g3, and the lifting movement of the yokes P need thus be relatively slight.

In the method and mechanism of chain formation herein described, the side bars of the links are not in anv way deformed or bent until the step succeeding that in which the final severing of both hook tongues from the side bars is completed. This bending occurs, in the' case of the pintle bar, at the step before the blank is severed, and in case of the hook bar at the step when the blank is severed. Thus throughout most of its excursion between punch and die the stock is straight edged, and can be easil and `eiicient- 1y forwardly fed through the 's otted yokes or guides P.

The stri of metal stock of which the links are forme is a fibrous material and, though tough and hard, is relatively yielding to impacts parallel to the grain of its fibers and is likely to tear along the line of the fibers, if i weakened therealong. Thus it is necessary not only to render easy the severing of the parts which have to be severed, and to make this severing possible without a damaging distortion of the material, but also to limit the severing and to counteract the tendency for further and unintended tearing or sever ing, either during manufacture or during the later use of the chain. To make the severing easy, some of the parts to be severed are initially scored. To prevent unintended tearing, the lines of score are terminated by creases or indentations which modify the normal fibrous structure of the material, and which prevent the formation of lines and angles of weakness and cleavage.

The successive steps of the operation may be summarized as follows:

First step: The top of the stock is prick punched or indented at the future point of separation of the hook tongue and the side bars as at g5. I illustrate a sharp pointed punch, but obviously a blunt or rounded punch may be used. At the same time the tongue g 1s sheared from the side bars and the future pintle bar and its outer end is slightly bent by the form and action of the punch G, being severed from the side bars' for part, shownin the drawings as about twothirds, of its length. The pintle bar is left 1n the plane of the stock and is not severed,

but scored both on the top and bottom by the .v

scores (1 gl which outline the separation between the pintle bar and the side bars.

Second step: The hook tongue q is thrown upwardly from the stock, although it is not further severed from the side bars. The

separation between the unsevered portion of` the tongue and the side bars is outlined on the top and bottom by the scores h* ht. The pintle tongue h is severed from the side bars and upwardly bent about the creasing bead H` forming the crease h3 in the stock.

Third step The hook tongue is now conipletely severed from the side bars, being sheared along the scores h* h5 clear back to the prick punch marks g. The pintle tongue is thrown upwardly about the creasing bead J3 into substantial perpendicularity to the stock.

Fourth step: At this step the hook tongue and end bar are not operated on, but the pintle tongue is bent into -final position and llll at the same time and by the same action the whole pintle bar is bent downwardly from the plane of the stock into its final osition.

Fifth step: The blank, with its pintle end completed, is now severed from the stock. The spring pads L engage the side bars and 'fiold the blank in osition. Thev hook end bar is bent substantially into final shape and the hook ton ue is thrown still further around, or hig er from the stock. The completed pintle end is surrounded by the hook tongue of the precedingly severed link. v

Sixth step-r At this step the uncompleted link, which was at the preceding stepqoined to the chain, and drawn forwardly with it,` is

. positioned on a slightly rearwardly inclined die memmber, being clamped thereon by the sprin ads C1, The hook tongue is then rolle about the pintle of the succeeding link into its final'cylindrical form, and the link is l thus completed.

In the tools herein described I employ massive robust punch and die elements which are not rapidly worn and can be used for relatively long periods Without replacement. Taking the members from right to left of Figure 5, the'prick punch points are durable. The punch G is a massive member and exerts a shearing action a ainst the edge G2 of the die G1. The die 1 is a massive block and the shearing action is practically the easiest and least wearing type of action on the opposed elements. rlhe die H is a massive member with no sharp edges or corners to weer o asis the die member il. rIhe creasing beads H3 I3 are not subjected to articular wear. The wear on the knife i is re duced by giving it a shearing action against the opposed uncli. The various arcuate forming members are not particularly sub-- ject to wear. Thus I have developed a peculiarl robust and long lived set of tools.

Whi e I have illustrated a practical and operable set of tools it will be realized that many changes may be made in the details and arrangements of the individual elements and their relative size and location without departing from `the spirit of my invention and I wish inv drawings and description to be 'taken as in a broad sense diagrammatic or illustrative rather than as limiting meto my specific showing.

I claim: 1. In a machine for making, from a. continuous strip of sheet metal stock, chain links having intles and hooks struck from the center o the link, comprising an opposed die and punch, each having a. plurality of eifements positioned therealong for progressivel action upon the' stock passing therebetween means for initially severing the outer end o the hook'tongue from the side bars and the o posed edge of the future pintle bar, and at t e same time scoring the separation between the side bars and the pintle tongue; means.

for bending the scored pintle tongue from the side bars and for scoring the separation belink.

2. In a machine for making, from a co'n tinuous strip of sheet metal stock, chain links having intles and hooks struck from the center o the link, comprising an o posed die and punch, each havin a plurality of elements positioned therea ong for progressive action upon the stock passing therebetween, means for initially severing the outer end of the hook tongue from the side bars and the l opposed edge of the future pintle bar and for crimping the end of said hook tongue, and at the same time scoring the separation between the side bars and the pintle tongue, means for bending the scored pintle tongue from the sidebars, and for creasin the inside of the bend thereby formed, an at the same time scoring the separation between the un severed portion of the hook tongue and the side bars; means for completin the se aration of the hook tongue from t e side ars;

means vfor forming the pintle tongue and pintle end bai' into ianl shape; means for crimping the hook end bar and substantially simultaneously severing the link from the stock and curling around its pintle the hook tongue of the precedingly severed link.

3. In a machine for making, from a continuous strip of sheet metal stock, chain'links having Pintles and hooks struck from the center o the link, comprising anopposed die and punch, each having a plurality ,of elements positioned-therealong for progressive action upon the stock passing therebetween, means for initially severing the outer end of the hook tongue from the side bars, while maintaining the rest of the hook tongue and the future pintle tongue in the plane of the link; means fory bending the pintle tongue from the side bars and for scoring the separation between the unsevered portion of the hook tongue and the side bars; means for completing the separation of the hook tongue from the side bars; means for forming the pintle tongue and pintle end bar into final shape; means for substantiallyy simultaneously Severin the link from the stock and curling aroun its pintle the hook tongue of the precedingly severed link." v

4. In a machine for making, from a continuous strip of sheet metal stock, chain links having intles and hooks struck from the center o the link, comprising an opposed die and punch, each having a plurality of elelll@ ments positioned therealong for progressive action upon the stock assing therebetween, means for initialy in entin the inner corners of the hook ton ue and te side bars, and scoring the lines o separation between the pintle tongue and the side bars, and bending the hook tongue from the side bars along part of its length and orimpin the outer end of the hook tongue; means or separating the pintle tongue from the side bars alon said scores an bending it from the 1in and creasing the inside of the bend thus formed, and for scoring the lines of separation between the side bars and the unsevered portion of the hook tongue; means for com leting the separation of the hook tongue a. ong

\ said lines of score; means for forming the fil 

